The overall objective of the proposed research is to study mechanisms and details of aromatization in placenta, ovary and brain and to study control and interaction of ovarian cells. Specific objectives are to: 1) Continue work on solubilization of placental cytochrome P-450, 2) Study placental aromatase kinetics, 3) Study steroidogenesis and interaction between ovarian cells especially in the human ovary, 4) Study metabolism of medroxyprogesterone and megesterol, and 5) Continue work on evolution of brain aromatization.